Detecting Parasites Loads in Urine Diversion Toilets. by David James Hawksworth Submitted in fulfillment of the academic requirements for the degree of MASTER OF SCIENCE in the Faculty of Science and Agriculture School of Biological and Conservation Sciences University of KwaZulu Natal Durban South Africa May 2009
Foreword but worms are very unglamorous things, you talk of faeces and you talk of latrines, and there s no fashionable side to worms. You can always find a politician and policy makers who will love to come to open a brand new cardiac unit. Everybody s very willing to have a paediatric wing named after them or a special renal unit named after them. Just find someone who wants to have a toilet named after them, then you will control ascariasis (Kan, 1989 in Crompton et al., 1989 a ). a Crompton DWT, Nesheim MC and Pawloski ZS (1989). Ascariasis and its prevention and control. Taylor and Francis, London. ii
Abstract In an attempt to supply sanitation to the growing communities in rural and peri-urban areas around Durban, the ethekweni Municipality has installed urine diversion (UD) toilets which have been modified to suit local conditions. These toilets are based on the ecological sanitation (EcoSan) system. The future aims are to reuse waste as a composting medium and minimize the use of water but the presence of microorganisms in the faecal waste poses a potential health risk to people in contact with it. Currently the Municipality has not deemed the waste safe for re-use but has suggested that after a one year standing period it should be free of all potential pathogens including Ascaris lumbricoiodes (human roundworm) ova. This study reports on the development of the AMBIC protocol for the recovery of Ascaris ova from the standing vaults of UD toilets. The protocol has been shown to consistently recover over 70% of Ascaris ova and has the added advantage of recovering the ova of other helminth species (Trichuris trichiura and Taenia sp.) present in a UD standing vault sample. Recoveries of Ascaris ova and ova of other parasite species, namely Trichuris and Taenia sp., are reported from waste which has been standing for one year. This is cause for concern as it shows one year is not a sufficient standing period to render the waste free of all microorganisms. Sampling from 124 UD toilet vaults that were in use, showed a high prevalence of both helminth (Ascaris lumbricoiodes, Trichuris trichiura and Taenia sp.) and protozoan (Giardia and Cryptosporidium) parasites.. iii
Preface The experimental work described in this thesis was carried out in the School of Biological and Conservation Sciences, University of KwaZulu-Natal from January 2006 to January 2008, under the supervision of Professor M.T. Smith and Dr N. Rodda. These studies represent original work by the author and have not otherwise been submitted in any form for any degree or diploma to any tertiary institution. Where use has been made of the work of others it is duly acknowledged in the text. Candidate: David James Hawksworth.. Supervisor: Professor Michael Smith. Supervisor: Dr Nicola Rodda.. iv
Acknowledgements Firstly, to my parents who supported me through this project from the beginning and continue to do so. As they would always remark that my brother and I were always in shit, it was just the depth that mattered. When I announced that I was going to make shit my career, they were not surprised. Go figure..... To my brother, Richard, wish you were here to see me submit. The long distant calls were always a great support, especially in the trying times. Dr Nicola Rodda for her support and opportunities to travel as a member of the Pollution Research Group (PRG). Professor Mike Smith for his continued interest, support and going off at a tangent ideas. The many conversations held in your office about totally unrelated subjects will forever linger with me. It is a pleasure to be your last Masters student enjoy retirement, you deserve it! Now you have an even better reason to sample the Johnnie Walker. It s not because you do have to look at my papers...... Professor Chris Buckley for his continued support, both during my research and the many visits to the Oyster Bar to discuss research. The introductions you have afforded me and the aspects and implications of my research that you have shown me that cannot be taught in a lecture theatre. I am in a better position than most students at this level because of it thank you!! Your speeches on the 5 rules of being a Masters student and it s just a shitty Masters will remain with me for many years to come. Professor Thor-Axel Stenström for continued advice and opportunities he has given for me to travel during my Masters and for my future PhD work. Without your continued advice I surely would be in the working world by now... v
Professor Chris Appleton for the use of his lab during my experiments and for his continued interest in my project. Your willingness to share knowledge and expertise with me cannot be thanked enough! To Colleen (a.k.a. Mrs A, Senior Shit Stirrer, Ouma and the Ou Tannie ), I could dedicate an entire chapter to you! You have taught me everything I know and I still know nothing? Where would I be without your cups of tea and treats surely insane by now! You have not gotten rid of me yet and we still have loads more talking to do...... I am forever grateful for your generosity!! To fellow students in the PRG group for their continued support and motivation. Sudhir and Sharon, you get a special mention here... The ethekwini Municipality for funding this project and logistical assistance. Mr Teddy Gounden and Mr Lucky Sibiya get a special mention here... vi
Table of Contents Foreword... ii Preface... iii Acknowledgements... v Chapter 1: Background 1.1. General Introduction... 1 1.2. Structure of Dissertation... 2 Chapter 2: Introduction 2.1. Setting the Scene... Error! Bookmark not defined. 2.2. Current Sanitation Systems Available in South AfricaError! Bookmark not defined. 2.2.1. Waterborne... Error! Bookmark not defined. 2.2.2. On-site sanitation... Error! Bookmark not defined. 2.2.3. On-site sanitation provision by urine diversion toilets... Error! Bookmark not defined. 2.3. Sanitary Risks Associated with UD Faecal WasteError! Bookmark not defined. 2.3.1. Emptying the UD vault... Error! Bookmark not defined. 2.3.2. Pathogens associated with UD faecal waste... Error! Bookmark not defined. 2.4. The geohelminth Ascaris lumbricoides... Error! Bookmark not defined. 2.4.1. Distribution... Error! Bookmark not defined. 2.4.2. Morphology... Error! Bookmark not defined. 2.4.3. Life Cycle... Error! Bookmark not defined. 2.4.4. Pathology... Error! Bookmark not defined. 2.4.5. Link with Inadequate Sanitation... Error! Bookmark not defined. 2.5. Recovery of Ascaris lumbricoides... Error! Bookmark not defined. 2.5.1. Recovery principles... Error! Bookmark not defined. 2.5.2. Faecal samples... Error! Bookmark not defined. 2.5.3. Wastewater samples... Error! Bookmark not defined. 2.5.4. Towards and international standard method... Error! Bookmark not defined. 2.5.5. Recovery of Ascaris from UD waste... Error! Bookmark not defined. 2.6. References... Error! Bookmark not defined. Chapter 3: The Development of a Method for the Recovery of Ascaris Ova from Faecal Waste in Urine Diversion Toilets. 3.1. Abstract... Error! Bookmark not defined. 3.2. Introduction... Error! Bookmark not defined. 3.3. Materials and Methods... Error! Bookmark not defined. 3.3.1. Quantifying Ascaris ova in a sample... 27 3.3.2. Flotation test protocol using seeded samples... Error! Bookmark not defined. 3.3.3. Separating Ascaris ova from organic and siliceous residue the AMBIC protocol... 29 vii
3.3.4. Preparation of comparable environmental samples... 30 3.3.5. Comparison of AMBIC protocol with Visser Filter method... Error! Bookmark not defined. 3.3.6. Statistical methods... Error! Bookmark not defined. 3.4. Results and Discussion... Error! Bookmark not defined. 3.4.1. Quatifying Ascaris ova in a sample ussing standardised zinc flotation method... 31 3.4.2. Flotation test protocols... Error! Bookmark not defined. 3.4.3. Separating Ascaris ova from organic and siliceous residue: the AMBIC protocol... 38 3.4.4. Comparison of AMBIC protocol with Visser Filter method... Error! Bookmark not defined. 3.5. Conclusion and Recommendations 41 3.6. Acknowledgements... 41 3.7. References... 41 Chapter 4: Assessment of the Recovery Efficiency of the AMBIC Protocol. 4.1. Abstract... 44 4.2. Introduction... 44 4.3. Materials and Methods... 47 4.3.1. Experimental outline... 47 4.3.2. Recovery of Ascaris lumbricoides ova for inoculation... 47 4.3.3. Collection, preparation and inoculation of waste material... 48 4.3.4. Standard ZnSO 4 flotation and AMBIC protocol (Chapter 3)... 49 4.3.5. Visser Filter Method as outlined in Visser and Pitchford (1972)... 50 4.3.6. Total solids and ova/g UD waste calculations... 51 4.3.7. Statistical analysis... 52 4.4. Results and Discussion... 52 4.4.1. Inoculation and recovery of seeded samples... 52 4.4.2. Recovery of Ascaris from mixed standing UD vault waste... 54 4.4.3. Comparison of recoveries among seeded samples and mixed field samples... 56 4.4.4. Recovery of other species of helminth ova... 57 4.4.5. Small scale field trial using the AMBIC protocol... 59 4.4.6. Significance of brief field trial and future research... 63 4.5. Conclusions... 64 4.6. Acknowledgements... 64 4.7. References... 64 Chapter 5: Prevalence of Helminth and Protozoan Parasites in the Filling Vaults of Urine Diversion (UD) Toilets. 5.1. Abstract... 67 5.2. Introduction... 67 5.3. Materials and Methods... 69 5.3.1. Study sites... 69 5.3.2. Sampling procedure... 70 5.3.3. Screening for Giardia and Cryptosporidium... 70 5.3.4. Screening for helminths... 71 viii
5.3.5. Statistical analysis... 71 5.4. Results and Discussion... 71 5.4.1. Parasite prevalence... 71 5.4.2. Link of parasite prevalence to possible infection... 75 5.4.3. Limitations and statistical results... 76 5.5. Conclusions... 77 5.6. Acknowledgements... 78 5.7. References... 78 Chapter 6: Concluding Remarks 6.1. AMBIC Protocol... 81 6.2. Sampling from filling vaults of UD toilets... 82 6.3. Future research... 82 6.4. Closing remarks... 83 6.5. References... 84 G:\Varsity Work\Masters 2006 & 2007\New Masters Introduction.doc G:\Varsity Work\Masters 2006 & 2007\Chapter 3.DOC G:\Varsity Work\Masters 2006 & 2007\New Chapter 4.doc G:\Varsity Work\Masters 2006 & 2007\Chapter 5.doc ix
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